I have ran two different sources on Meso (Stanford and Symbiotics) and two sources on SST (Cascade and Hunter).
Cascade was PIP free and I wish he was still around. I can speak of Hunter’s because I have been mixing his DHB with another source, however, my buddy is running Hunter’s and he said it PIP free.
To minimize PIP you need to pin no more than 1ml and try to mix twitch test E or C.